X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Finclude_next.m4;h=5e22ded936ccb558203f81709e7b8f2417fd532f;hb=7becd9d708425924f3a402fdd3c6e18ba2a7e4e3;hp=91ecbb0965a2f6eee78fb96c6e99310860b180f3;hpb=d4cf26ba74a9072ac6d68b43272077a9f52d22c4;p=gnulib.git diff --git a/m4/include_next.m4 b/m4/include_next.m4 index 91ecbb096..5e22ded93 100644 --- a/m4/include_next.m4 +++ b/m4/include_next.m4 @@ -1,18 +1,20 @@ -# include_next.m4 serial 9 -dnl Copyright (C) 2006-2008 Free Software Foundation, Inc. +# include_next.m4 serial 14 +dnl Copyright (C) 2006-2009 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. dnl From Paul Eggert and Derek Price. -AC_PREREQ([2.60]) - dnl Sets INCLUDE_NEXT and PRAGMA_SYSTEM_HEADER. dnl dnl INCLUDE_NEXT expands to 'include_next' if the compiler supports it, or to dnl 'include' otherwise. dnl +dnl INCLUDE_NEXT_AS_FIRST_DIRECTIVE expands to 'include_next' if the compiler +dnl supports it in the special case that it is the first include directive in +dnl the given file, or to 'include' otherwise. +dnl dnl PRAGMA_SYSTEM_HEADER can be used in files that contain #include_next, dnl so as to avoid GCC warnings when the gcc option -pedantic is used. dnl '#pragma GCC system_header' has the same effect as if the file was found @@ -28,12 +30,27 @@ AC_DEFUN([gl_INCLUDE_NEXT], AC_LANG_PREPROC_REQUIRE() AC_CACHE_CHECK([whether the preprocessor supports include_next], [gl_cv_have_include_next], - [rm -rf conftestd1 conftestd2 - mkdir conftestd1 conftestd2 - dnl The include of is because IBM C 9.0 on AIX 6.1 supports - dnl include_next when used as first preprocessor directive in a file, - dnl but not when preceded by another include directive. - cat < conftestd1/conftest.h + [rm -rf conftestd1a conftestd1b conftestd2 + mkdir conftestd1a conftestd1b conftestd2 + dnl IBM C 9.0, 10.1 (original versions, prior to the 2009-01 updates) on + dnl AIX 6.1 support include_next when used as first preprocessor directive + dnl in a file, but not when preceded by another include directive. Check + dnl for this bug by including . + dnl Additionally, with this same compiler, include_next is a no-op when + dnl used in a header file that was included by specifying its absolute + dnl file name. Despite these two bugs, include_next is used in the + dnl compiler's . By virtue of the second bug, we need to use + dnl include_next as well in this case. + cat < conftestd1a/conftest.h +#define DEFINED_IN_CONFTESTD1 +#include_next +#ifdef DEFINED_IN_CONFTESTD2 +int foo; +#else +#error "include_next doesn't work" +#endif +EOF + cat < conftestd1b/conftest.h #define DEFINED_IN_CONFTESTD1 #include #include_next @@ -49,27 +66,36 @@ EOF #endif #define DEFINED_IN_CONFTESTD2 EOF - save_CPPFLAGS="$CPPFLAGS" - CPPFLAGS="$CPPFLAGS -Iconftestd1 -Iconftestd2" + gl_save_CPPFLAGS="$CPPFLAGS" + CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1b -Iconftestd2" AC_COMPILE_IFELSE([#include ], [gl_cv_have_include_next=yes], - [gl_cv_have_include_next=no]) - CPPFLAGS="$save_CPPFLAGS" - rm -rf conftestd1 conftestd2 + [CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1a -Iconftestd2" + AC_COMPILE_IFELSE([#include ], + [gl_cv_have_include_next=buggy], + [gl_cv_have_include_next=no]) + ]) + CPPFLAGS="$gl_save_CPPFLAGS" + rm -rf conftestd1a conftestd1b conftestd2 ]) PRAGMA_SYSTEM_HEADER= if test $gl_cv_have_include_next = yes; then INCLUDE_NEXT=include_next + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next if test -n "$GCC"; then - dnl GCC 3.0 or newer supports #pragma GCC system_header. - PRAGMA_SYSTEM_HEADER='#if __GNUC__ >= 3 -#pragma GCC system_header -#endif' + PRAGMA_SYSTEM_HEADER='#pragma GCC system_header' fi else - INCLUDE_NEXT=include + if test $gl_cv_have_include_next = buggy; then + INCLUDE_NEXT=include + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next + else + INCLUDE_NEXT=include + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include + fi fi AC_SUBST([INCLUDE_NEXT]) + AC_SUBST([INCLUDE_NEXT_AS_FIRST_DIRECTIVE]) AC_SUBST([PRAGMA_SYSTEM_HEADER]) ]) @@ -78,8 +104,14 @@ EOF # For each arg foo.h, if #include_next works, define NEXT_FOO_H to be # ''; otherwise define it to be # '"///usr/include/foo.h"', or whatever other absolute file name is suitable. +# Also, if #include_next works as first preprocessing directive in a file, +# define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be ''; otherwise define it to +# be +# '"///usr/include/foo.h"', or whatever other absolute file name is suitable. # That way, a header file with the following line: # #@INCLUDE_NEXT@ @NEXT_FOO_H@ +# or +# #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@ # behaves (after sed substitution) as if it contained # #include_next # even if the compiler does not support include_next. @@ -92,31 +124,43 @@ EOF AC_DEFUN([gl_CHECK_NEXT_HEADERS], [ AC_REQUIRE([gl_INCLUDE_NEXT]) + AC_REQUIRE([AC_CANONICAL_HOST]) AC_CHECK_HEADERS_ONCE([$1]) m4_foreach_w([gl_HEADER_NAME], [$1], [AS_VAR_PUSHDEF([gl_next_header], - [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME]))) + [gl_cv_next_]m4_defn([gl_HEADER_NAME])) if test $gl_cv_have_include_next = yes; then AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>']) else AC_CACHE_CHECK( - [absolute name of <]m4_quote(m4_defn([gl_HEADER_NAME]))[>], - m4_quote(m4_defn([gl_next_header])), + [absolute name of <]m4_defn([gl_HEADER_NAME])[>], + m4_defn([gl_next_header]), [AS_VAR_PUSHDEF([gl_header_exists], - [ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME]))) + [ac_cv_header_]m4_defn([gl_HEADER_NAME])) if test AS_VAR_GET(gl_header_exists) = yes; then AC_LANG_CONFTEST( [AC_LANG_SOURCE( [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]] )]) - dnl eval is necessary to expand ac_cpp. + dnl AIX "xlc -E" and "cc -E" omit #line directives for header files + dnl that contain only a #include of other header files and no + dnl non-comment tokens of their own. This leads to a failure to + dnl detect the absolute name of , , + dnl and others. The workaround is to force preservation of comments + dnl through option -C. This ensures all necessary #line directives + dnl are present. GCC supports option -C as well. + case "$host_os" in + aix*) gl_absname_cpp="$ac_cpp -C" ;; + *) gl_absname_cpp="$ac_cpp" ;; + esac + dnl eval is necessary to expand gl_absname_cpp. dnl Ultrix and Pyramid sh refuse to redirect output of eval, dnl so use subshell. AS_VAR_SET([gl_next_header], - ['"'`(eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD | - sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{ - s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1# + ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD | + sed -n '\#/]m4_defn([gl_HEADER_NAME])[#{ + s#.*"\(.*/]m4_defn([gl_HEADER_NAME])[\)".*#\1# s#^/[^/]#//&# p q @@ -127,7 +171,17 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS], AS_VAR_POPDEF([gl_header_exists])]) fi AC_SUBST( - AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))), + AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])), [AS_VAR_GET([gl_next_header])]) + if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then + # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next' + gl_next_as_first_directive='<'gl_HEADER_NAME'>' + else + # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include' + gl_next_as_first_directive=AS_VAR_GET([gl_next_header]) + fi + AC_SUBST( + AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_defn([gl_HEADER_NAME])), + [$gl_next_as_first_directive]) AS_VAR_POPDEF([gl_next_header])]) ])